JENG-DA CHAIHead-Gordon, MMHead-Gordon2018-09-102018-09-10200900219606http://scholars.lib.ntu.edu.tw/handle/123456789/346708https://www.scopus.com/inward/record.uri?eid=2-s2.0-70449378694&doi=10.1063%2f1.3244209&partnerID=40&md5=2a7b60fb0a4a2d03f718b864391ee5edWe extend the range of applicability of our previous long-range corrected (LC) hybrid functional, ωB97X [J.-D. Chai and M. Head-Gordon, J. Chem. Phys. 128, 084106 (2008)], with a nonlocal description of electron correlation, inspired by second-order Møller-Plesset (many-body) perturbation theory. This LC "double-hybrid" density functional, denoted as ωB97X-2, is fully optimized both at the complete basis set limit (using 2-point extrapolation from calculations using triple and quadruple zeta basis sets), and also separately using the somewhat less expensive 6-311++G (3df,3pd) basis. On independent test calculations (as well as training set results), ωB97X-2 yields high accuracy for thermochemistry, kinetics, and noncovalent interactions. In addition, owing to its high fraction of exact Hartree-Fock exchange, ωB97X-2 shows significant improvement for the systems where self-interaction errors are severe, such as symmetric homonuclear radical cations. © 2009 American Institute of Physics.Basis sets; Complete basis set limit; Density functionals; Hartree-Fock exchanges; Homonuclear; Hybrid density; Many-body; Non-covalent interaction; Nonlocal; Perturbation theory; Radical cations; Second orders; Self-interaction error; Training sets; Approximation theory; Perturbation techniques; Thermochemistry; Molecular physicsjournal article10.1063/1.32442092-s2.0-70449378694WOS:000271664500011